JPS60209539A - Nematic liquid crystal compound and liquid crystal composition - Google Patents

Abstract

NEW MATERIAL:The 2-alkyl-6-(4-alkoxymethylphenyl)-1,2,3,4-tetrahydronaphthalene compound of formula I (R<1> and R<2> are 1-10C alkyl). EXAMPLE:2-Propyl-6-(4-methoxymethylphenyl)-1,2,3,4-tetrahydronaphthalene. USE:Useful as a component of a liquid crystal composition. It forms a liquid crystal composition by mixing with a liquid crystal compound such as phenylcyclohexane-type liquid crystal, etc. A liquid crystal composition having low working voltage and excellent contrast can be prepared. PREPARATION:The compound of formula I can be prepared by brominating the acylated 4-acylbiphenyl of formula II, condensing with dimethyl malonate, hydrolyzing and decarbonating the condensation product, esterifying with methanol- sulfuric acid after reduction, carrying out the acetylation and oxidization of the product, cyclizing the product, and carrying out several steps such as reduction, esterification, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to novel nematic liquid crystal compounds and nematic liquid crystal compositions, and particularly to nematic liquid crystals suitable for liquid crystal display devices.

[Background of the invention]

In recent years, liquid crystal materials exhibiting a nematic phase have been used in display devices, such as watches, calculators, games, automobile instrument panels, and even TVs.

When using a liquid crystal material as a material for a display body, it is common practice to mix several types of liquid crystal compounds and use the mixture as a liquid crystal composition. As is already known in the art, liquid crystal compounds exhibiting various physical properties are mixed to satisfy the characteristics necessary for display. That is, properties are improved by mixing various liquid crystal compounds in appropriate combinations.

However, at present, it is difficult to satisfy all important performance requirements for a display device, such as a wide operating temperature range, fast response speed, and good display quality.

[Purpose of the invention]

An object of the present invention is to provide a liquid crystal compound suitable for producing a nematic liquid crystal composition as described above and a liquid crystal composition containing the compound.

[Summary of the invention]

The liquid crystal compound according to the present invention is a 2-alkyl-6-(β-alcogysimethylphenyl)-1,2,3,4-nato9-human of phthalene compound represented by the general formula (1), and is It has physical and chemical stability that is important for use.

The present inventors conducted detailed studies on the correlation between the physical properties and chemical structure of nematic liquid crystals, obtained knowledge regarding the chemical structure, and achieved the present invention.

The liquid crystal compound according to the present invention is a novel compound discovered by the present inventors, and is synthesized, for example, according to the synthesis flow sheet shown below.

That is, acylation (cJVerrltt e
ial, l or, gl SYn, , Co11.
Vol, , IV 8 (1963), etc.)
-Acylbiphenyl is brominated and condensed with malonic acid dimethyl ester, followed by hydrolysis and decarboxylation to yield β-alkyl-β-(4-biphenylcarbonyl)propionic acid. Next, hydrate and reduce with dorazine-caustic potassium,
After esterification with methanol-sulfuric acid, acetylation and oxidation were carried out with β-alkyl-bonyl-4'-biphenisol) butyric acid. Subsequently, the residue is ring-closed with polyphosphoric acid, and reduction and esterification reactions are performed to obtain 2-alkyl-6-(-methquinecarponylphenyl)-1,2,3.4-tetrahydronaphthalene. Next, the methoxycarbonyl group is reduced with lithium aluminum hydride, chlorinated, and etherified with sodium alcoholade to obtain the desired 2-alkyl-6-(
i-alkoxymethylphenyl)-1,2,3,4-tetrahydronaphthalene/ is obtained.

The liquid crystal compound of the present invention can be mixed with known liquid crystal compounds such as biphenyl-type liquid crystal, phenylcyclohexane-type liquid crystal, phenylbenzoate-type liquid crystal, and phenylcyclohexanecarboxylate-type liquid crystal to form a liquid crystal composition in a free mixing ratio. Furthermore, optically active substances, dichroic dyes, etc. can also be contained.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, in the following examples, physical property values such as phase transition temperature may vary slightly depending on the purity of the synthesized compound, the measuring method, etc.

(Example 1) 2-propyl-6-(-methoxymethylphenyl) -
The method for producing 1,2,3,4-tetrahydronaphthalene and its phase transition temperature are shown below.

(a) Synthesis of 4-(α-bromo)valeryl biphenyl 10
Dissolve 0g of bromine in a mixed solvent of 300cc of chloroform and 200cc of acetic acid, and add 7% of bromine under stirring while keeping the temperature below 20C.
4 g was added dropwise. After the bromine color of the reaction solution disappeared, the reaction solution was poured into water and neutralized with an aqueous solution of caustic soda. Next, extraction was performed using chloroform, and after washing with water and drying, the chloroform was distilled off.

The residue was recrystallized from isopropyl alcohol to give 4-(α
-bromo) valeryl biphenyl (m, p, 82.6-84.4C) (b) Synthesis of 1-(4'-biphenylcarbonyl)butyl dimethyl malonate Dissolve 26 g of sliced metallic sodium in 300 g of dimethyl malonate. Set aside and cook for 40 to 50 minutes while stirring.
Then, 300 g of 7'C4-(α-bromo)valeryl biphenyl was added dropwise to 600 cc of benzene, and stirring was continued for 4 hours at 11 degrees Celsius after the dropwise addition.

Next, the reaction solution was poured into water and acidified with hydrochloric acid.
The +I benzene layer was separated, washed with water, and dried.

Benzene and excess dimethyl malonate were distilled off under reduced pressure to obtain 320 g of crude 1-(4'-biphenylcarbonyl)butyl dimethyl malonate.

(C) Synthesis of 1-(4'-biphenylcarbonyl)butylmalonic acid + fl 280g of dimethyl 1-(4'-biphenylcarbonyl)butylmalonate in methanol 500CC11
The mixture was mixed with 1000 cc of an aqueous solution of 0.0% caustic soda and stirred under reflux for 5 hours. The reaction solution was poured into water and acidified with hydrochloric acid, and then the liberated oil layer was extracted with chloroform. The chloroform layer was washed with water and dried, and after distilling off the chloroform, the residue was left to crystallize. The crystals were washed with benzene to obtain 264 g of crude 1-(4'-biphenylcarbonyl)butylmalonic acid.

(d) Synthesis of β-(4-biphenylcarbonyl)-β-propyl-propionic acid 230g of crude 1-(4'-biphenylcarbonyl)butylmalonic acid was stirred at 180 to 200C for 5 hours, and after cooling, benzene was added. The precipitated crystals were collected. Next, 172 g of the obtained crystals were stirred under reflux for 2 hours with 500 cc of methanol and 500 cc of an 8 tCl aqueous sodium hydroxide solution. The reaction solution was poured into water and acidified with hydrochloric acid, and then the liberated oil layer was extracted with chloroform. After the chloroform layer was washed with water and dried, the residue obtained by distilling off the chloroform was poured into hexane and crystallized. The crystals were collected in F and crude β-(4-biphenylcarbonyl)-β-propylpropionic acid 130
I got g.

(m, p, 89-c+26c) (e) Synthesis of methyl γ-(4-biphenylyl)-β-propylbutyrate 75 g of β-(4-biphenylcarbonyl)-β-propylpropionic acid, 50 g of 80% hydrazine hydrate, 150 g Caustic potassium aqueous solution 70g 1 diethylene glycol 500c
c was mixed and stirred under reflux for 3 hours. Next, the temperature was raised to 200 to 210C while removing the distillate, and stirring was continued at the same temperature for an additional 4 hours.

The mixture was poured into cold drained water, acidified with hydrochloric acid, extracted with benzene, and the benzene layer was washed with water and dried, and then the benzene was distilled off.

The residue was stirred under reflux for 4 hours with 500 cc of methanol and 5 cc of sulfuric acid, and then the reaction solution was poured into water and extracted with benzene. After washing and drying the benzene layer, the benzene was distilled off and the residue was distilled under reduced pressure to obtain γ-(4-biphenylyl).
-50 g of methyl β-propylbutyrate was obtained.

(b, I), 167C10, 3-pharyngeal Hg) (f) γ-(
Synthesis of methyl 4-acetyl-4'-biphenylyl)-β-propylbutyrate Methylene chloride, 34 g of anhydrous aluminum chloride, and 13 g of acetyl chloride were mixed and stirred, and γ-(4-biphenylyl)- A solution of 32 g of methyl β-propylbutyrate in methylene chloride (4Qcc) was slowly added 9 drops while maintaining the temperature of the reaction solution at 0 to 5C, and stirring was continued for 3 hours after the addition was completed. Next, the reaction solution was poured into dilute hydrochloric acid and stirred, and the methylene chloride layer was separated, washed with water, and then stirred.
Dry. After distilling off the methylene chloride, the residue was recrystallized from acetone to obtain 21 g of methyl γ-(4-acetyl-4'-biphenylyl)-β-propylbutyrate.

(m, I), 68-71C) (g) Synthesis of γ-(4-hydroxycarbonyl-47-biphenylyl)-β-propylbutyric acid Dissolve 42 g of caustic soda in 200 cc of water, cool to below ioC, and dissolve bromine 4
6 g was added dropwise to prepare a sodium hypobromite solution.

420 g of γ-(4-acetyl-4'-biphenylyl)-β-propyl M was dissolved in 1 oocc of dioxane, and the sodium hypobromite sewage prepared above was added dropwise thereto with stirring. During this time, the reaction solution is cooled with water and kept at 20-30C. After the dropwise addition was completed, the temperature of the reaction solution was raised to 60C over 2 hours, and stirring was continued for 2 minutes at the same temperature. Next, sodium sulfite 2
After adding 120 cc of an aqueous solution of 0 g to decompose excess sodium hypobromite, acidifying with hydrochloric acid, the precipitated crystals were collected and washed with water to give crude γ-(4-hydroxycarbonyl-4'-
20 g of (biphenylyl)-β-propylbutyric acid was obtained.

(m, p, 214-218U) (h) Synthesis of 2-furopyru-6-(-hydroxycarbonylphenyl)-4-tetralone 280 g of polyphosphoric acid
20 g of γ-(4-hydroxycarbonyl-4'-biphenylyl)-β-propylbutyric acid was stirred and dispersed, and 1
Stirring was continued for 1.5 hours at 30-140C. After cooling, excess polyphosphoric acid was decomposed by gradually adding cold water, and the precipitated crystals were extracted with chloroform. After washing the chloroform layer with water and drying, chloroform was distilled off to obtain crude 2-7'ropyru-6-(-hydroxycarbonylphenyl)-4-
Tetralone 20, g obtained.

(i) Synthesis of 2-propyl-6-(-methoxycarbonylphenyl)-1,2,3,4-tetrahydronaphthalene Crude 2-propyl-6-(-hydroxycarbonylphenyl)-4-te)ralon 20 g - , 15 g of 80% hydrazine hydrate, 20 cc of 50% aqueous potassium hydroxide solution, and 150 cc of diethylene glycol were mixed and refluxed for 3 hours with stirring. Next, while removing the distillate, the reaction solution was heated to 200~
The temperature was raised to 210 tl, and stirring was continued at the same temperature for 4 hours. After cooling, the reaction solution was poured into water to make it acidic with hydrochloric acid, and the precipitated crystals were extracted with chloroform. After washing the chloroform layer with water and drying, chloroform was distilled off, and the resulting residue was refluxed for 6 hours with 200 cc of methanol and 2 cc of sulfuric acid.
Stir for hours. Next, the reaction solution was poured into water, benzene extraction was performed, and the benzene layer was washed with water and dried, and then the benzene was distilled off. The residual sound was put into acetone, the cine solution was removed by a separate furnace, and the residual sound after distilling off the acetone was distilled under reduced pressure, and then recrystallized from methanol to give 2-propyl-6-(-methoxycarbonylphenyl). 6 g of -1,2,3,4-tetrahydronaphthalene was obtained.

(m, I), 97.8-99. sc) This compound exhibits a nematic liquid crystal phase between 99.5 and 100C.

(j) Synthesis of 2-furopyru-6-(-hydroxymethylphenyl)-1,2,3,4-tetrahydronaphthalene 1 g of lithium aluminum hydride was suspended in 3 Qcc of anhydrous tetrahydrofuran, and 2-propyl-
6-(-methoxycarbonylphenyl)-1,2,3,
A solution of 6 g of 4-tetrahydronaphthalene and 5 c"c of tetrahydronaphthalene was added dropwise with stirring, and
Stirred at 5C for 2 hours. The reaction solution was poured into dilute hydrochloric acid, and ether was added to the liberated tetrahydrofuran layer. After separating the ether layer, it was washed with water and dried, the ether was distilled off, and the residual sound was recrystallized from acetone to obtain 2-propyl-6-(-hydroxymethylphenyl)-1,2°3.4-tetrahydronaphthalene 4 I got .5g.

(l]].p, io7.s~109.3C) (k) 2
-furopyru6-(-chloromethylphenyl) -1,
Synthesis of 2,3,4-tetrahydronaphthalene Benzene 59 cc, thionyl chloride 5g 1 Pyridine 0
．． A solution of 4.5 g of 2-propyl-6-(-hydroxymethylphenyl)-1,2,3゜4-tetrahydronaphthalene in benzene (5Qcc) was added dropwise under reflux while stirring. , and continued refluxing for 2 hours. After cooling, the reaction solution was poured into water and neutralized with an aqueous solution of caustic soda. The liberated benzene layer was separated, washed with water and dried, and then benzene was distilled off to obtain crude 2-propyl-6-(-chloromethylphenyl)-1,2,3,4-tetrahydronaphthalene 4.
I got g.

(m, I), 68-71.5 C)(cy2-propyl-6-(-methoxymethylphenyl)-1,2,3
, 4-tetrahydronaphthalene synthesis 30 cc of methanol sliced into 30 cc of sodium metal 0.
A solution of 1.5 g of 2-propyl-6-(-chloromethylphenyl)-1,2°3.4-tetrahydronaphthalene in benzene (15 cc) was added dropwise to this solution with stirring, and then 50 g of Heated to ~55C and continued stirring for 3 hours.

Thereafter, the reaction solution was poured into water, acidified with hydrochloric acid, extracted with benzene, washed with water, dried, and then benzene was distilled off. The residual sound was distilled under reduced pressure and further recrystallized with acetone to obtain the desired 2-propyl-6-(-methoxymethylphenyl)-1.
, 1 g of 2,3,4-tetrahydronaphthalene was obtained.

The elemental analysis values of this compound are C: 85.1%, II: 9.
0chi and the theoretical values (C: 85.67chi, H: 8.9chi), and a molecular ion peak was observed at 294 in the mass spectrum. From the relationship between these facts and the starting state, it was confirmed that this compound was the desired substance.

As a result of measuring the phase transition temperature of this compound, it transitioned from a crystalline phase to a nematic phase at 49.7 C, and transitioned from a nematic phase to an isotropic liquid phase at 52.8 tT.

(Example 2) Example 1 - (Ethyl alcohol to replace methanol)
2-propyl-6-(
-ethoxydimethylphenyl)-1° was obtained.

The compound melted at 4.1.5C and upon cooling transitioned from an isotropic liquid phase to a nematic phase at 32C.

(Example 3) Example 1-(2-propyl-6-
(-propoxymethylphenyl)-1,2,3,4-tetrahydronaphthalene was obtained.

This compound has a melting point of 32.8 C, and when cooled after melting, it transitions from an isotropic liquid phase to a nematic phase at 31.20 C.

Furthermore, by using appropriate raw materials in the same manner as in Example 1, the following compounds can also be easily synthesized.

2-Methyl-6-(p-methoxymethylphenyl)-1
,2,3,4-tetrahydronaphthalene 2-methyl-6
-(p-ethoxymethylphenyl)-1,2,3,4-
Tetrahydronaphthalene 2-methyl-er-(p-propoxymethylphenyl)-1,2,3,4-tetrahydronaphthalene/2-methyl-6-(p-butoxymethylphenyl)-1,2,3,4- Tetrahydronaphthalene 2-methyl-6-(p-pentoxymethylphenyl)-
1,2,3,4-tetrahydronaphthalene 2-may-
Ru6-(p-hexyloxymethylphenyl)-1y
2,3.4-Tetrahydronaphthalene 2-methyl-6-(p-hebutyloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene 2-methyl-6-(p-octyloxymethylphenyl)-1 ,2,3,4-tetrahydronaphthalene 2-methyl-6-(p-nonyloxymethylphenyl)
-1,2,3,4-tetrahydronaphthalene 2-methyl-6-(p-decyloxymethylphenyl)
-1,2,3,4-tetrahydronaphthalene 2-: r-f
Ru-6-(p-methoxymethylphenyl)-1,2,3
, 4-tetrahydronaphthalene 2-ethyl-6-(p-
ethoxymethylphenyl)-1,2,3,4-tetrahydronaphthalene2-ethylh-6-(p-propoxymethylphenyl)-1,2,3,4-tetrahydronaphthalene2-ethyl-6-(p-butoxy methylphenyl)-
1,2,3,4-tetrahydronaphthalene 2-ethyl-
6-(p-pentoxymethylphenyl) -1,2,3
, 4-tetrahydronaphthalene 2-ethyl-6-(p-
hexyloxymethylphenyl)-'1,2,3.4-
Tetrahydronaphthalene 2-ethyl-6-(p-hebutyloxymethylphenyl)-1,2,3,4-Tetrahydronaphthalene 2-ethyl-6-(p-octyloxymethylphenyl)-1,2,3,4 -tetrahydronaphthalene 2-ethyl-6-(p-/nyloxymethylphenyl)
-1,2,3,4-tetrahydronaphthalene 2-:r-(ru-6-(p-f syloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene 2-propyl-6-(p-butoxy methylphenyl) 1
,2,3.4-tetrahydronaphthalene 2-propyl-
6-(p-pentoxymethylphenyl)-1,2,3,
4-Tetrahydronaphthalene 2-propyl-6-(p-hexyloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene 2-propyl-6-(p-heptyloxymethylphenyl)-1,2,3 , 4-tetrahydronaphthalene 2-propyl-6-(p-octyloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene 2-propyl-6-(p-nonyloxymethylphenyl i-1,2,3 ,4-tetrahydronaphthalene2-propyl-6-(p-decyloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene2-butyl-6-(p-methoxymethylphenyl)-1
,2,3,4-tetrahydronaphthalene 2-but-6-(p-ethoxymethylphenyl)-1,2,3,4
-Tetrahydronaphthalene 2-butyl-6-(p-propoxymethylphenyl)' + 21314-Tetrahydronaphthalene 2-butyl-6-(p-butoxymethylphenyl)-1,2,3,4-tetrahydronaphthalene 2-phf (6-(p-hey)keymethylphenyl)
-1,2,3,4-tetrahydronaphthalene 2-butyl-6-(p-hexyloxymethylphenyl)-1,2
, 3,4-tetrahydronaphthalene 2-fuy-ru-6-(p-hebutyloxymethylphenyl) -1,2,3,4-tetrahydronaphthalene 2-butyl-6-(p-octyloxymethylphenyl)- 1,2,3,4-tetrahydronaphthalene 2-butyl-6-6([)-nonyloxymethylphenyl) -1,2,3,4-tetrahydronaphthalene 2-butyl-6,-(p-decyloxymethyl phenyl)-1,2,3,4-tetrahydronaphthalene2-pentyl-6-(p-methoxymethylphenyl)-
1,2,3,4-tetrahydronaphthalene 2-hentyl-6-(p-ethoquinomethylphenyl)-1,2,3,
4-tetrahydronaphthalene 2-henthia 1z-6-(
p-propoxymethylphenyl)-1,2,3,4-
Tetrahydronaphthalene 2-benthyl 6--ft-(p-butoxymethylphenyl)-1,2,3,4-tetrahydronaphthalene 2-pentyl-6-(p-pentoxymethylphe=/L=)-
1,2,3,4-tetrahydronaphthalene 2-pentyl-6-(p-hexyloxymethyl 7x=
-1,2,3,4-tetrahydronaphthalene2-pentyl-6-(p-hebutyloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene2-pentyl-6-(p-octyloxymethyl phenyl)-1,2,3,4-tetrahydronaphthalene2-pentyl-6-(p-nonyloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene2-pentyl-6-(p-decyloxymethyl phenyl) 1.2,3.4-tetrahydronaphthalene2-hexyl-6-(p-methoxymethylphenyl)-
1,2,3,4-tetrahydronaphthalene 2-hexyl-6-(p-ethoxymethylphenyl) -'l, 2,
3.4-tetrahydronaphthalene 2-heginru 6-(
1)-propoxymethylphenyl)-1,2,3,4-
Tetrahydronaphthalene 2-hexyl-6-(p-butoxymethylphenyl)-
1,2,3,4-tetrahydronaphthalene 2-hequinru6-(p-pentoxymethylphenyl)-1,2,3
,4-tetrahydronaphthalene2-hexyl-6-(p-hexyloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene2-hexyl-6-(p-hebutyloxymethylphenyl)-1 ,,2,3,4-tetrahydronaphthalene2-hexyl-6-(p-octyloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene2-hexyl-6-(p-nonyloxymethylphenyl )-1,2,3,4-tetrahydronaphthalene2-hexyl-6-(p-decyloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene2-hebutyl-6-(p-methoxymethyl phenyl)−
1,2,3,4-tetrahydronaphthalene 2-hephthyl-6-(p-ethoxymethylphenyl)-1,2,3,
4-tetrahydronaphthalene 2-hectyl-6-(1)
-7'lopoxymethylphenyl)-1,2,3,4-
Tetrahydronaphthalene 2-hebutyl-6-(p-butoxymethylphenyl)-
1,2,3,4-tetrahydronaphthalene 2-hephthyl-6-(p-pentoxymethylphenyl)-1,2,3
, 4-tetrahydronaphthalene 2-hebutyl-6-(p-hexyloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene 2-hebutyl-6-(p-hexyloxymethylphenyl)-1 ,2,3,4-tetrahydronaphthalene2-hectyl-6-(p-octyloxymethylphenyl)1,2,3.4-tetrahydronaphthalene2-hephthyl-6-(p-nonyloxymethylphenyl)-1, 2,3,4-Tetrahydronaphthalene 2-hefnal-6-(p-decylox7methylphenyl)-1,2,3,4-tetrahydronaphthalene 2-octyl-6-(p-methquinmethylphenyl)-
1,'2,3,4-tetrahydronaphthalene 2-#rif
Ru-6-(p-ethoxymethylphenyl)-1,2,3
, 47 Tetrahydronaphthalene 2-o”f-6-(p
-propoxymethylphenyl) -1,2,3,4-tetrahydronaphthalene2-octyl-6-(p-butoxymethylphenyl)-
1,2,3,4-tetrahydronaphthalene 2=-A-rif-6-(p-pentoxymethylphenyl)-1,2
,3,4-tetrahydronaphthalene 2-octyl-6-(p-hexyloxymethylphenyl)-1,,2,3,4-tetrahydronaphthalene 2-octyl-6-(p-heptyloxymethylphenyl)-1 , 2,3,4-tetrahydronaphthalene 2-octyl-6-(p-octyloxy/methylphenyl)-1,2,3,4-tetrahydronaphthalene 2-octyl-6-(p-nonyloxymethylphenyl)-1 ,2,3,4-tetrahydronaphthalene2-octyl-6-(p-decyloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene2-/=ru'-6-(p-methquinmethylphenyl )-1,2,3,4-tetrahydronaphthalene2-nonyl-6-(p-ethoxymethylphenyl)-1,2,
3,4-tetrahydronaphthalene 2- / = Roux
5-(p-furboxymethylphenylpheny#)-1,2,
3,4-tetrahydronaphthalene 2-/=nyl--(p
-))xymethylphenyl)-1,2,3,4-tetrahydronaphthalene2-/=nyl--(p-pentoxymethylphenyl)-1,2,3,4-tetrahydronaphthalene2-nonyl-6= (p-hexyloxymethylphenyl), -1,2,3,4-tetrahydronaphthalene 2-nonyl-6-(p-hexyloxymethylphenyl)-1,2,3,4-tetrahydronaphthalene 2- / =Rou6-(p-octyloxymethylphx=R)-1,2,'3,4-tetrahydronaphthalene2-nonyl-6-(p-nonyloxymethylph=/l
/)-1e 2,3.4-tetrahydronaphthalene 2-nonyl-6-(p-decyloxymethylphenyl)
-1,2,3,4-tetrahydronaphthalene 2-decyl-6"(, p-methoxymethylphenyl)-
1,2,3,4-tetrahydronaphthalene 2-decyl-
6-'(p=ethoxymethylphenyl)-1,2,3,
4-tetrahydronaphthalene 2-decyl-6-(p-propoquinemethylphenyl)-1,2,3,4-tetrahydronaphthalene 2-decyl-6-' (p-butoxymethylphenyl)-1,2,3, 4-tetrahydronaphthalene 2-decyl-6-(p-pentoxymethylphenyl)-1,2,3,4-tetrahydronaphthalene 2-decyl-6-(p-hexyloxymethylphenyl)-1,
2,3,4,-Tetrahydronaphthalene 2-decyl-6-(p-hebutyloxymethylphenyl) -1,2,3,4-tetrahydronaphthalene 2-decyl-6-(p-octyloxymethylphenyl, = c.
-1,2,3,4-tetrahydronaphthalene 2-tesol-6-(p-nonyloxymethylphenyl)
"1,2,3,4-tetrahydronaphthalene 2-decyl-6-(p-decyloxymethylphenyl)
-1,2,3,4-tetrahydronaphthalene Also, when the liquid crystal compound obtained above was mixed, 2-furovyl-6-(-ethoquinomethylphenyl)-1,2,3,
4-tetrahydronaphthalene and 2-furopyru-6-(-
The liquid crystal blackness range of the equimolar mixture (mixture A) of propoxymethylphenyl-1,2,3,4-tetrahydronaphthalene is 16.3 to 30.8. The value of tl: is shown.

Furthermore, 2-propyl-6-(-methoxymethylphenyl)-1,2,3,4-tetrahydronaphthalene 60 mol% naphthalene 60
The mixture consisting of molch (mixture B) is from below OC to 41
It became a nematic liquid crystal phase in the temperature range of C, and the refractive index anisotropy of mixture B was 0.12 at 20C.

-(trans-
T N (Twist
el Nemetic) type display was created and its operating performance was investigated, and it was found that it could be operated at low voltage and was capable of displaying negative contrast. Therefore, it has been revealed that a liquid crystal composition that enables good display can be obtained by using the compound of the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, a high-quality liquid crystal display that can operate at low voltage and is immersed in contrastContinued from page 1 @ Inventor Akio Mukao @ Inventor Yoshi 1) Masahiro @ Inventor Kenji Suzuki 0 shots Akira Hisashi Okawa ■Inventor Tsunenobu Fujii 3-1-1 Saiwai-cho, Hitachi City Hitachi, Ltd. Hitachi Research Co., Ltd. 3-7 Nihonbashi-honmachi, Chuo-ku, Tokyo Kanto Kagaku Co., Ltd. 3-7 Nihonbashi-honmachi, Chuo-ku, Tokyo Address Kanto Kagaku Co., Ltd. 3-7 Nihonbashi Honcho, Chuo-ku, Tokyo Kanto Kagaku Co., Ltd.

Claims (1)

[Scope of Claims] 1. A liquid crystal compound represented by the general formula (wherein R1 and R2 are alkyl groups having 1 to 10 carbon atoms). 2. A liquid crystal composition containing a liquid crystal compound represented by the general formula (wherein 1 and R2 are alkyl groups having 1 to 10 carbon atoms).